Replication and availability in decentralised online social networks
Issue Date
2017Subjects
G420 Networks and Communicationssocial network
social networking
decentralised architecture
online social networks
Metadata
Show full item recordAbstract
During the last few years’ online social networks (OSNs) have become increasingly popular among all age groups and professions but this has raised a number of issues around users’ privacy and security. To address these issues a number of attempts have been made in the literature to create the next generation of OSNs built on decentralised architectures. Maintaining high data availability in decentralised OSNs is a challenging task as users themselves are responsible for keeping their profiles available either by staying online for longer periods of time or by choosing trusted peers that can keep their data available on their behalf. The major findings of this research include algorithmically determining the users’ availability and the minimum number of replicas required to achieve the same availability as all mirror nodes combined. The thesis also investigates how the users’ availability, replication degree and the update propagation delay changes as we alter the number of mirror nodes their online patterns, number of sessions and session duration. We found as we increase the number of mirror nodes the availability increases and becomes stable after a certain point which may vary from node to node as it directly depends on the node’s number of mirror nodes and their online patterns. Moreover, we also found the minimum number of replicas required to achieve the same availability as all mirror nodes combined and update propagation delay directly depends on mirror nodes’ number of sessions and session duration. Furthermore, we also found as we increase the number of sessions with reduced session lengths the update propagation delay between the mirror nodes starts to decrease. Thus resulting in spreading the updates faster as compared to mirror nodes with fewer sessions but of longer durations.Citation
Hassan, A. (2017) 'Replication and availability in decentralised online social networks'. MPhil thesis. University of Bedfordshire.Publisher
University of BedfordshireType
Thesis or dissertationLanguage
enDescription
A thesis submitted to the University of Bedfordshire in partial fulfilment of the requirements for the degree of Master of PhilosophyCollections
The following license files are associated with this item:
- Creative Commons
Except where otherwise noted, this item's license is described as http://creativecommons.org/licenses/by-nc-nd/4.0/
Related items
Showing items related by title, author, creator and subject.
-
Spatial diversity for wireless LANsWireless local area networks (W-LAN) are widely used as a means of providing broadband access for high-speed wireless data services. The maximization of the system performance independent of the transceiver technology and the operating environment is of utmost importance to the hotspot system designer. This paper reports on the performance of single input and multiple output (SIMO) W-LAN systems and shows that a circular array topology located at the access point provides the best performance improvement compared to other candidate technologies when operating in an indoor office environment.
-
Performance analysis of routing protocols in ManetThe history of wireless network is around 20 year old, when in 1997 IEEE start working on it and define the wireless standards in 1999. As Mobile Adhoc Network (MANET) is self managing and governing network, so it is the challenging task to handle the network in most effective and better way due to dynamic changes In the network as the nodes can join and leave the network without getting any authorization and these nodes are independent in nature. This research is based on the performance measurement of proactive and reactive protocols with respect to quality of service.
-
Cross-validation based man-in-the-middle attack protectionIn recent years, computer network has widely used in almost all areas of our social life. It has been profoundly changing the way of our living. However, various network attacks have become an increasingly problem at the same time. In local area networks, Man-in-the-Middle attack, as one kind of ARP attack, is the most common attack. This research implemented a cross-validation based Man-in-the-Middle attack protection method (CVP). This approach enables a host to check whether another host that responds the initialising host with an ARP reply packet is genuine. It then allows the ARP cache table of the initialising hosts to be updated with the MAC address and IP address pairs of the genuine host and to place the MAC address of inauthentic hosts into a blacklist. This research introduced ARP and ICMP firstly, including the structure of ARP and ICMP packets, and their workflows. Secondly, this research discussed the types of ARP attacks and the existing ARP attacks protection methods, including their principles, applicable environment, advantages and disadvantages. Then, this research proposed and implemented a cross-validation based Man-in-the-Middle attack protection method. Simulations and experiments were performed to examine the effect of CVP method. The results show the effectiveness of the proposed cross-validation based method in protecting network from Man-in-the-Middle attack. Compared with the existing Man-in-the-Middle attack protection methods, CVP requires no extra devices and administration, leading to more secure local area networks and low cost. It also has made a “tabu” to attackers. That is, it places the MAC address of attackers into a blacklist. So they will be identified immediately if they try to attack the network again.
